In reply to your question, as I said in my previous post, the reason I have been thinking about Tantalum or even Niobium Oxide capacitors is because even the best electrolytic capacitors will leak at some point. Sure, it may take 15 years, but they will leak and need to be replaced. Solid tantalums on the other hand, will last longer (assuming they are properly voltage derated). Leaking caps is a major issue in vintage computing, not because the caps are old tech. Even new tech can and will leak at some point. Leaky caps often will eat through traces on the PCB. This happens often in vintage Macs. So again, that's why I'm pondering all my replacement options at this point. Physical size is a concern though, since the existing PCB pads are only 6.5mm, measured outer edge to outer edge.